Griffen castle was built between 1124 and 1146 by order of Bishop Otto of Bamberg. In an 1160 deed, Emperor Friedrich I mentioned Grivena as a Bamberg property.
In 1292 the Carinthian nobleman Count Ulrich von Heunburg with support of Archbishop Konrad IV of Salzburg occupied the fort in an uprising against Albert of Habsburg, the son of King Rudolph I of Germany and Duke Meinhard II. However Ulrich was abandoned by his allies and one year later had to leave the castle. In 1759 Bishop Adam Friedrich sold the Bamberg estates in Carinthia to Maria Theresa of Austria and the castle was incorporated into the Carinthian duchy.
About 1520 a large reconstruction of the castle took place as a protection against the threat posed by the Ottoman forces with a base amounted of about 4000 m², though the Turks never laid siege to Griffen. In 1659 a flash impact destroyed one of the towers and the decay of the castle began. In 1768 a last religious service took place and about 1840 the roofs were torn. In 2000 the preservation of the castle began. A steep footpath leads up the mountain to the ruins.
Within the mountain is the Griffener Tropfsteinhöhle (dripstone cave) with a length of 485m, which was not discovered until the late days of World War II. It is open to public and a natural landmark since 1957.
References:The ancient Argos Theater was built in 320 BC. and is located in Argos, Greece against Larissa Hill. Nearby from this site is Agora, Roman Odeon, and the Baths of Argos. The theater is one of the largest architectural developments in Greece and was renovated in ca 120 AD.
The Hellenistic theater at Argos is cut into the hillside of the Larisa, with 90 steps up a steep incline, forming a narrow rectilinear cavea. Among the largest theaters in Greece, it held about 20,000 spectators and is divided by two landings into three horizontal sections. Staircases further divide the cavea into four cunei, corresponding to the tribes of Argos A high wall was erected to prevent unauthorized access into the theatron and may have helped the acoustics, but it is said the sound quality is still very good today.
Around 120 CE, both theaters were renovated in the Roman style.